• 1923 – 1927

    Teachers' Institute in Spišská Kapitula (composing – Fraňo Dostalík)

  • 1929 – 1949

    rehearsal pianist in various theatres in the Czech Republic and Moravia

  • 1949

    return to Slovakia

  • since 1949

    teacher of music and arts at the grammar school in Bardejov and rehearsal pianist of the Ukrainian Song and Dance Group

  • 1952

    comeback on the Slovak music scene as a composer (the opera The Unawakened One)

  • since 1954

    rehearsal pianist of the Ukrainian National Theatre

  • since 1957

    secretary of the Košice branch of the Slovak Composers Union

“For the composer-philosopher Grešák the basis of composition is “the cellule”, and a composition itself is actually a pulsation of musical cellules whose relationship is the purpose of composing. In the foreground is the metro-rhythmic dimension of music, which in conjunction with the revised structure (an influence of Webern) and functional instrumentation creates a musical process, characterized by extraordinary vitality and originality. Grešák put his ideas into an original notation form, so his pieces can be performed after transcribing into conventional notation, which was done by B. Režucha, thereby actually demonstrated the ideal collaboration of composer and performer. Režucha endeavored not only to revive Grešák's music, but also to increase the author's confidence and usher in an explosion of his last creative period. Grešáks' ideas were the basis of his chamber, orchestral and stage works. All of the ideas of Grešáks' operas come from classical works of Slovak literature (Kukučín, Hviezdoslav, Šikula) and their common denominator is the social aspect of collective resistance against different, “strange – other” individuals(the mentally challenged, orphans), as well as a collective of personal sacrifice of the weakest innocent as the supreme manifestation of the dehumanization of a person. None of Grešáks' operas have yet been performed on stage, however Slovak musical institutions consistently put into practice Grešák's ideas of stage compositions.”


(GODÁR, Vladimír: Jozef Grešák. In: 100 slovenských skladateľov. Ed. Marián Jurík, Peter Zagar. Bratislava : Národné hudobné centrum, 1998, p. 111 – 112.)